Bibcode
Asorey, M.; Garcia-Alvarez, D.; Lopez, J. L.
Referencia bibliográfica
eprint arXiv:hep-th/0406234
Advertised on:
6
2004
Número de citas
0
Número de citas referidas
0
Descripción
Quantum fluctuations generate in three-dimensional gauge theories not
only radiative corrections to the Chern-Simons coupling but also
non-analytic terms in the effective action. We review the role of those
terms in gauge theories with massless fermions and Chern-Simons
theories. The explicit form of non-analytic terms turns out to be
dependent on the regularization scheme and in consequence the very
existence of phenomena like parity and framing anomalies becomes
regularization dependent. In particular we find regularization regimes
where both anomalies are absent. Due to the presence of non-analytic
terms the effective action becomes not only discontinuous but also
singular for some background gauge fields which include sphalerons. The
appearence of this type of singularities is linked to the existence of
nodal configurations in physical states and tunneling suppression at
some classical field configurations. In the topological field theory the
number of physical states may also become regularization dependent.
Another consequence of the peculiar behaviour of three-dimensional
theories under parity odd regularizations is the existence of a simple
mechanism of generation of a mass gap in pure Yang-Mills theory by a
suitable choice of regularization scheme. The generic value of this mass
does agree with the values obtained in Hamiltonian and numerical
analysis. Finally, the existence of different regularization regimes
unveils the difficulties of establishing a Zamolodchikov c-theorem for
three-dimensional field theories in terms of the induced gravitational
Chern-Simons couplings.